The extra double meaning behind Casca’s “it was Greek to me” also aims to reveal his class, or rather lack of it. Rome was a bilingual empire and society, who’s 2 main languages were Greek AND Latin, and interchangeable at that. Casca not being able to understand the Greek language shows him to be non cultured, non educated, and a thug. All Romans of Patrician class spoke mainly Greek and some ONLY Greek, Caesar himself being one. As also there was a common Greek being spoken and learned on the streets as well, in the markets etc etc, Latin was THE vulgar language of the street, of the people, and not of the ruling classes, but of the plebs. And “High Latin” or “Classical Latin” was just newly codified by Cicero himself during this age, as part of some nationalist efforts to give some prestige to Latin, by copying Greek forms in order to give Latin a class and status comparable to Greek. Livy writes in “high” or ‘classical” Latin. People like Casca not only didn’t speak Greek, but their Latin was probably just as bad in comparison to the “high Latin” of Cicero, Livy and the likes. Hence, the unaccomplished, thug conspirator slays the very accomplished and very cultured Caesar. Caesar’s last words to Brutus are also a sort of pun. Caesar spoke Greek when he was murdered, if anything at all. In the play Shakes paraphrases the lines in Latin, not English, implying another language. Just as Caesar spoke those words to Brutus in an other language, that being Greek. “And you Brute?” was actually, “You too, child?” if anything at all.